Small Triambic Icosahedron

I am totally addicted to folding paper and pretty soon origami progress reports are going to take over my blog.

I made this small triambic icosahedron yesterday afternoon using 30 Sonobe units and these instructions. Basically it looks like an icosahedron (20 equilateral triangle faces) with a small tetrahedron on top of each of the faces. This polyhedron is also called the first stellation of the regular icosahedron.

Truncated Icosahedron

Meet the latest addition to my origami family. It’s a truncated icosahedron (12 pentagon faces, 20 hexagon faces, 90 edges, 60 vertices) i.e. a soccer ball. I made this one using Pentagon-Hexagon Zig-Zag (PHiZZ) units from this site. Achieving “proper 3-edge colouring” was definitely not easy. I was close several times and each time had to disassemble a chunk of the polyhedron and start again. If any of you C&O-types know a good algorithm for colouring polyhedron edges please let me know because right now I’m depending on brute force. The end result does make it all worthwhile though.

Dodecahedron

More paper folding fun! I made this dodecahedron (12 pentagon faces, 30 edges, 20 vertices) last night using instructions from this site. I really like the colouring I used – each vertex joins edges of the three different colours so that no two adjacent edges of a pentagon are the same colour. I guess the graph theory in Math 239 has finally come in handy!

Look what I made!

How cool is that? Those are 5 intersecting tetrahedra made entirely by folding paper – no glue or tape.

I’ve decided that I’m not allowed to start another origami project until I get moving on knitting the second sleeve of my sweater. Folding paper is just so much fun though!